As an inkjet printer head, for example, there is known a side shooter type device serving as a share mode share wall type inkjet printer head equipped with nozzles at the lateral side of a pressure chamber. Such an inkjet head includes a substrate, a frame member adhered to the substrate, a nozzle plate adhered to the frame member, a piezoelectric member adhered to the substrate at a position inside the frame member and a head drive IC for driving the piezoelectric member. In the printing process, the piezoelectric member is driven, and pillars serving as driving elements arranged at both sides of each pressure chamber in the piezoelectric member are curved by performing shear mode deformation, and in this way, the ink in the pressure chamber is pressurized, and ink drops are ejected from the nozzles.
In a case of a conventional inkjet printer head in which a soft nozzle plate made of resin is fixed on the piezoelectric member, the nozzle plate may also be deformed when each pressure chamber in the piezoelectric member is deformed. As a result, there is a possibility that part of the driving force of the piezoelectric member is used for the deformation of the nozzle plate.
Further, there is also an inkjet printer head in which, for example, a metal lid member with high rigidity is arranged between the piezoelectric member and the nozzle plate. In this case, the fixing part of the lid member and the pressure chamber is firmly connected, in this way, it is possible to prevent that part of the driving force of the piezoelectric member is used for the deformation of the nozzle plate and that the ink ejection efficiency is decreased.
However, the conventional inkjet printer head does not pay much attention to the relation between the nozzle diameter of the nozzle plate serving as a resin member with nozzles and the diameter of through holes of the metal lid section laminated on the nozzle plate.